<div>
    <style>
        .wi-row > div{ border: solid 1px #ccc;}
    </style>
    <div class="wi-row">
        <div class="wi-col-1">1</div>
        <div class="wi-col-2">2</div>
        <div class="wi-col-3">3</div>
        <div class="wi-col-6">6</div>
    </div>
    <br />
    <div class="wi-row">
        <div class="wi-col-2">1</div>
        <div class="wi-col-2">2</div>
        <div class="wi-col-2">3</div>
        <div class="wi-col-2 wi-offset-4">2 offset-4</div>
    </div>
    <br />
    <div class="wi-row">
        <div class="wi-col-1">1</div>
        <div class="wi-col-2">2</div>
        <div class="wi-col-3">3</div>
    </div>
</div>